Apparatus, system and method for improving position estimation and/or communication performance in a wireless communication network

ABSTRACT

An apparatus includes an antenna and a transceiver. The transceiver transmits a first signal via the antenna, the first signal including a unique identification of the apparatus and a request for receive information about the first signal at a receiver. The transceiver receives from the receiver a second signal via the antenna, the second signal including first information about a direction of arrival (DoA) of the first signal at the receiver and second information indicative of a location of the receiver.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/712,670, filed Dec. 12, 2019, which is a continuation of copendingInternational Application No. PCT/EP2018/064770, filed Jun. 5, 2018,which is incorporated herein by reference in its entirety, andadditionally claims priority from European Application No. EP 17 176075.4, filed Jun. 14, 2017, which is incorporated herein by reference inits entirety.

BACKGROUND OF THE INVENTION

The present invention concerns the field of wireless communicationnetworks or systems, and embodiments relate to apparatus, systems andmethods for providing information allowing for an improved positionestimation, and/or for providing an improved communication performanceof the entities within the communication network, and/or for improvingperformance of MIMO (Multiple Input Multiple Output) systems.

FIG. 1 is a schematic representation of an example of a wireless network100 including a core network 102 and a radio access network 104. Theradio access network 104 may include a plurality of base stations eNB₁to eNB₅, each serving a specific area surrounding the base stationschematically represented by respective cells 106 ₁ to 106 ₅. The basestations are provided to serve users within a cell. A user may be astationary device or a mobile device. Further, the wirelesscommunication system may be accessed by IoT devices which connect to abase station or to a user. The mobile devices or the IoT devices mayinclude physical devices, ground based vehicles, such as robots or cars,aerial vehicles, such as manned or unmanned aerial vehicles (UAVs), thelatter also referred to as drones, buildings and other items havingembedded therein electronics, software, sensors, actuators, or the likeas well as network connectivity that enable these devices to collect andexchange data across an existing network infrastructure. FIG. 1 shows anexemplary view of only five cells, however, the wireless communicationsystem may include more such cells. FIG. 1 shows two users UE1 and UE2,also referred to as user equipment (UE), that are in cell 106 ₂ and thatare served by base station eNB₂. Another user UE₃ is shown in cell 106 ₄which is served by base station eNB₄. The arrows 108 ₁, 108 ₂ and 108 ₃schematically represent uplink/downlink connections for transmittingdata from a user UE₁, UE₂ and UE₃ to the base stations eNB₂, eNB₄ or fortransmitting data from the base stations eNB₂, eNB₄ to the users UE₁,UE₂, UE₃. Further, FIG. 1 shows two IoT devices 110 ₁ and 110 ₂ in cell106 ₄, which may be stationary or mobile devices. The IoT device 110 ₁accesses the wireless communication system via the base station eNB₄ toreceive and transmit data as schematically represented by arrow 112 ₁.The IoT device 110 ₂ accesses the wireless communication system via theuser UE₃ as is schematically represented by arrow 112 ₂. The respectivebase station eNB₁ to eNB₅ are connected to the core network 102 viarespective backhaul links 114 ₁ to 114 ₅, which are schematicallyrepresented in FIG. 1 by the arrows pointing to the “core”. The corenetwork 102 may be connected to one or more external networks.

The wireless communication system may be any single-tone or multicarriersystem based on frequency-division multiplexing, like the orthogonalfrequency-division multiplexing (OFDM) system, the orthogonalfrequency-division multiple access (OFDMA) system, or any otherIFFT-based signal with or without CP, e.g. DFT-s-OFDM. Other waveforms,like non-orthogonal waveforms for multiple access, e.g. filter-bankmulticarrier (FBMC), generalized frequency division multiplexing (GFDM)or universal filtered multi carrier (UFMC), may be used. In the wirelesscommunication system a transmission time interval (TTI) may be defined,e.g., 1 ms or less. The TTI is the granularity at which the data may bemapped from higher layers to the physical layer (PHY) to perform thetransmission.

In a wireless communication network, like the one depicted in FIG. 1 ,it may be desired to locate a UE, like a drone, with a certain accuracyin a cell. When considering the example of a drone, the wirelesscommunication network may cover a specific area, like one or morestreets along which the drone is to travel, e.g., autonomously. Therespective cells of the wireless communication network may cover partsof the respective streets, and the base stations serving the respectivecells may be provided along the streets, e.g., the base stations may bemounted to lamp posts located along the street. For example, forautonomous traveling or for providing position information to anoperator, the drone needs to determine its position within a cell. Oneapproach to locate a UE, like a drone, within a cell or a certain areais based on an observed time difference of arrival (OTDOA) estimationthat may be used in cellular communication networks, such as LTE, andwhich is a downlink positioning method that relies on the calculation oftime of arrival (TOA) estimates using position reference signals (PRS)receives at the user equipment UE from one or more surrounding basestations (eNB), as is described, for example, in references [1] and [2].PRS sequences are downlink signals that are designed for positioningpurposes and that are broadcast to all radio terminals within a cell.The PRS sequences are radiated with the same transmit power from theantenna of the base station or the remote radio head (RRH) in alldirections to cover all users at any location of the cell, i.e., toprovide a cell-wide coverage. To distinguish the PRS sequences fromdifferent cells, each PRS sequence has associated therewith acell-specific identifier also referred to as a physical cell identifier(PCI). The PCI is unique in a specific area and is used to identify thecell and thus the PRS sequence. At least three timing measurements fromgeometrically dispersed base stations are needed, relative to the UE'sinternal time base, in order to obtain a unique position in a plane.Four base stations are needed to obtain a unique position in athree-dimensional space as is described in reference [3].

In addition to the above mentioned approaches for a position estimationof mobile devices, another process is based on GNSS (Global NavigationSatellite System) and is described in reference [4]. Yet another processfor a position estimation of mobile devices may be based on measurementsof the SNR/RSSI (Signal-to-Strength Ratio/Receive Signal StrengthIndicator) in WiFi or Bluetooth networks.

As described above, position estimation within a specific area may bedesired for mobile devices. Among such mobile devices there may bemobile devices having a low or reduced processing capacity or power anda limited energy source, like a battery. An example of such mobiledevices with low processing and energy are drones which may travel at ahigh speed. For such fast moving mobile devices the position may beestimated for security and privacy reasons, and a continuous update ofthe position update with a high periodicity/frequency may be desired.

While the above described approaches for estimating a position mayprovide satisfactory results, they come with several drawbacks. Forexample, all of the approaches described in references [1] to [4] needthe mobile device to perform measurements and calculations forestimating the position, which may not be feasible for devices havinglimited processing and battery capacity. Also, the calculation may betime consuming so that once the position has been estimated, the actualposition already changed. This may be true especially for fast movingmobile devices. For example, the GNSS approach described in referencegoes together with a huge power consumption of the GNSS receivers, andit may take several seconds to obtain a first position using such GNSSreceivers. Further, signal from the GNSS may not be available indoors,such as construction halls. Also, the GNSS may not be precise enough inenvironments in which the signals from the respective satellites are notdirectly received, as it may be the case in urban environments, such asin street canyons. Making use of SNR/RSSI measurements from a WiFi or aBluetooth network needs an additional WiFi or Bluetooth receiver at themobile device. In addition, such time of flight (ToF) based approachesneed a tight synchronization between the transmitter and the receiverwhich may be hard to achieve.

Another issue regarding the wireless communication network described inreference to FIG. 1 , is that the base stations used for serving therespective mobile devices UEs may provide for 3D beamforming or for afull dimension MIMO approach. This may be implemented in systemsoperating in accordance with the current LTE-Advanced pro standard orthe 5G or NR (New Radio) standard. To implement 3D beamforming, a basestation may include two-dimensional active antennas, as is described indetail in references [5] and [6]. To reduce the dimension of a channel,so-called grid-of-beam (GOB) concepts may be used to form effectiveantennas, as is outlined in reference [7]. Such beams are supposed to bestable over at least some time, like several tens of seconds. Dependenton the number of antennas and the array geometry such beams may havesmall half-power-beam widths (HPBWs). In such scenarios, in case amobile device is communicating with the base station, either for anuplink (UL) or for a downlink (DL) communication, the mobile device isnot necessarily exactly located in the direction of the main lobe of thebeams provided by the base station, and this may be due to the smallhalf-power-beam widths of the beams provided by the antenna array.Therefore, the performance of a communication between the mobile deviceand the base station may be deteriorated, for example, there may be aloss in the signal-to-noise ratio, either at the base station or at themobile device, dependent on whether a UL- or DL-communication isperformed.

Other approaches for estimating a position of a mobile device aredescribed in references [8] to [11].

SUMMARY

According to an embodiment, an apparatus may have an antenna; and atransceiver, wherein the transceiver is configured to transmit a firstsignal via the antenna, the first signal including a uniqueidentification of the apparatus and a request for receive informationabout the first signal at a receiver, and receive from the receiver asecond signal via the antenna, the second signal including firstinformation about a direction of arrival (DoA) of the first signal atthe receiver and second information indicative of a location of thereceiver.

According to another embodiment, an apparatus may have an antenna; and atransceiver, wherein the transceiver is configured to receive from atransmitter a signal via the antenna, the signal including informationabout a direction of a main lobe of the signal transmitted by thetransmitter, and a signal processing unit configured to estimate adirection of a main lobe of the signal received from the transmitter,and to indicate, using a position of the apparatus and the estimateddirection of the main lobe of the signal, a direction in which theapparatus should move to improve a communication with the transmitter.

According to another embodiment, an apparatus may have a plurality ofantennas; and a transceiver, wherein the transceiver is configured toreceive a first signal via the plurality of antennas, the first signalincluding a unique identification of a transmitter of the first signaland a request for receive information about the first signal at theapparatus, estimate a direction of arrival (DoA) of the first signal,and transmit to the transmitter a second signal via the plurality ofantennas, the second signal including first information about theestimated direction of arrival (DoA) of the first signal at theapparatus and second information indicative of a location of theapparatus.

According to another embodiment, a wireless communication network mayhave: an entity including an apparatus, including an antenna; and atransceiver, wherein the transceiver is configured to transmit a firstsignal via the antenna, the first signal including a uniqueidentification of the apparatus and a request for receive informationabout the first signal at a receiver, and receive from the receiver asecond signal via the antenna, the second signal including firstinformation about a direction of arrival (DoA) of the first signal atthe receiver and second information indicative of a location of thereceiver; and a base station including an apparatus of claim 15.

According to another embodiment, a method may have the steps of:transmitting a first signal via an antenna of a transmitter, the firstsignal including a unique identification of the transmitter and arequest for receive information about the first signal at a receiver,and receiving, from the receiver, a second signal via the antenna of thetransmitter, the second signal including first information about adirection of arrival (DoA) of the first signal at the receiver andsecond information indicative of a location of the receiver.

According to another embodiment, a method may have the steps of:receiving a first signal via the plurality of antennas of a receiver,the first signal including a unique identification of a transmitter anda request for receive information about the first signal at thereceiver, estimating a direction of arrival (DoA) of the first signal atthe receiver, and transmitting to the transmitter a second signal viathe plurality of antennas, the second signal including first informationabout the estimated direction of arrival (DoA) of the first signal atthe receiver and second information indicative of a location of thereceiver.

Another embodiment may have a non-transitory digital storage mediumhaving a computer program stored thereon to perform the method havingthe steps of: transmitting a first signal via an antenna of atransmitter, the first signal including a unique identification of thetransmitter and a request for receive information about the first signalat a receiver, and receiving, from the receiver, a second signal via theantenna of the transmitter, the second signal including firstinformation about a direction of arrival (DoA) of the first signal atthe receiver and second information indicative of a location of thereceiver, when said computer program is run by a computer.

Another embodiment may have a non-transitory digital storage mediumhaving a computer program stored thereon to perform the method havingthe steps of: receiving a first signal via the plurality of antennas ofa receiver, the first signal including a unique identification of atransmitter and a request for receive information about the first signalat the receiver, estimating a direction of arrival (DoA) of the firstsignal at the receiver, and transmitting to the transmitter a secondsignal via the plurality of antennas, the second signal including firstinformation about the estimated direction of arrival (DoA) of the firstsignal at the receiver and second information indicative of a locationof the receiver, when said computer program is run by a computer.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be detailed subsequentlyreferring to the appended drawings, in which:

FIG. 1 shows a schematic representation of an example of a wirelesscommunication system;

FIG. 2 is a schematic representation of an embodiment of the firstinventive aspect in which a mobile device, responsive to a beacon signalsent to a bases station, receives from the base station information thatmay be used estimating its position and/or improving the performance ofa communication with the base station;

FIG. 3 is a schematic representation of an embodiment of the inventiveapproach for estimating a position of a mobile device;

FIG. 4 depicts a further embodiment of the inventive approach inaccordance with which the information provided from the base stationtowards the mobile device UE is used for improving the communicationbetween the mobile device UE and the base station;

FIG. 5 is a schematic representation of a wireless communication systemfor transmitting information from a transmitter to a receiver; and

FIG. 6 illustrates an example of a computer system on which units ormodules as well as the steps of the methods described in accordance withthe inventive approach may execute.

DETAILED DESCRIPTION OF THE INVENTION

In the following, preferred embodiments of the present invention aredescribed in further detail with reference to the enclosed drawings inwhich elements having the same or similar function are referenced by thesame reference signs.

In accordance with a first aspect of the present invention, anapparatus, like a mobile device, sends out a first signal, like a beaconsignal, that is received at a receiver, like a base station. The firstsignal is uniquely associated with the apparatus and includes a requestfor first signal receive information, i.e. information about thespecifics of how the first signal is received by the receiver. Thereceiver, responsive to the first signal, generate a second signal orresponse signal that is unique for the apparatus, which had send thefirst signal, and that includes the requested first signal receiveinformation and information allowing the apparatus to determine alocation or position of the receiver, which sends out the second signal.In accordance with embodiments of the first aspect of the presentinvention, based on the response signal or the information conveyed bythe response signal, the apparatus, like the mobile device, may estimateits position and/or may improve the performance of a communication withthe receiver, like the base station. of the entities within thecommunication network, and/or for improving performance of MIMO(Multiple Input Multiple Output) systems.

In accordance with the first aspect the present invention provides anapparatus, like a mobile device, which includes an antenna and atransceiver, wherein the transceiver transmits a first signal via itsantenna which includes a unique identification of the apparatus, and arequest for receiving information about the first signal at a receiver,like a base station. The transceiver receives from the receiver a secondsignal via the antenna, which includes first information about adirection of arrival of the first signal at the base station and secondinformation indicative of a location of the base station.

In accordance with the first aspect the present invention provides anapparatus, like a base station, which includes a plurality of antennas,and a transceiver, wherein the transceiver receives a first signal viathe plurality of antennas which includes a unique identification of atransmitter, like a mobile device, of the first signal and a request forreceive information about the first signal at the apparatus. Thetransceiver estimates a direction of arrival of the first signal, andtransmits to the transmitter a second signal via the plurality ofantennas, which includes first information about the estimated directionof arrival of the first signal at the apparatus and second informationindicative of a location of the apparatus.

In accordance with embodiments of the second aspect, a mobile device maysend out a beacon signal which is unique for the mobile device, forexample by providing a unique identification. The beacon signal mayinclude a request telling the base station, at which the beacon may bereceived, that an estimation of the direction of arrival (DoA) of thesignal at the base station is to be performed. The DoA information isreturned to the mobile device together with positional information aboutthe base station.

In accordance with embodiments, the mobile device may estimate itsposition using the information included in the second signal. The mobiledevice may further determine a distance to the base station so that theposition may be estimated using the position of the base station, thedirection at which the beacon signal was received at the base stationand the distance to the base station. The distance may be determined bya measurement of the receive power of the second signal from the basestation and/or by a measurement of the time of arrival of the secondsignal. In accordance with embodiments, other known approaches fordetermining a distance to the base station may be employed by the mobiledevice. In accordance with yet other embodiments, the base station mayestimate its position responsive to information included in the signalfrom a plurality of base stations. In addition to receiving theinformation in the second signal from a first base station, theinformation may be received from a second and even more base stations, aposition of the mobile device may be estimated using of the informationin the plurality of second signals received at the mobile device. Inaccordance with yet further embodiments, when receiving a second signalfrom a plurality of base stations, the distances to the bases stationsmay be determined, as described above, and used in addition to theinformation in the second signals.

The position of the base station may be indicated in the response signalusing a unique identification or the actual position may be signaled. Incase the unique identification is provided to the mobile device, themobile station is allowed to access a table or a database including theactual position or location of a base station and the associatedidentification. This allows the mobile device, when accessing the database using the received identification, to determine the actual positionor location of the base station which may then be used for estimatingthe position. The DoA information may be provided as a unique directionvector or as values representing respective angles, such as horizontaland vertical angles, under which the first signal was received. Inaccordance with embodiments, the DoA information may be provided withrespect to a coordinate system in which the base station and the mobiledevice are located so as to take into account a relative orientation ofthe array antennas at the base station. The coordinate system may bereferred to as a reference coordinate system and may include a Cartesiancoordinate system, a polar coordinate system or a geographic coordinatesystem. For example, at the antenna array an angle at which the beamarrives at the antenna array may be indicated. The angle together withthe known orientation of the antenna array in the space defined by thereference coordinate system provides the DoA information.

The inventive approach for estimating the position is advantageous, asthe mobile device does not need to perform any major calculationsregarding received signals, rather, this processing is performed at thebase station which may have larger processing capabilities and acontinuous power supply. At the mobile device, on the basis of theinformation generated/calculated at the base station and transmitted tothe mobile device, the estimation of the position can be performed atreduced calculation efforts, thereby allowing, for example whenconsidering drones, small and lightweight processing units and stillallowing for a reliable estimation of the position of the drone. Thus,an energy-efficient and low-complex position estimation at the mobiledevice is enabled.

In accordance with yet further embodiments of the first aspect of thepresent invention, on the basis of the information received at themobile device in the second signal, the mobile device may estimate adirection to which a main lobe of a signal transmitted by the basestation is directed, and the signal processing unit in the mobile devicemay give an indication of a direction into which the mobile deviceshould be moved for improving the communication with the base station.This allows improving the communication, for example by improving theSNR or the wireless communication link.

In accordance with a second aspect of the present invention, anapparatus, like a base station, sends out, independent form any triggersignal from a mobile device, a beamformed signal including informationabout the direction of the signal or a main lobe of the signal. Forexample, in case the beam-direction of the base station is constant oversome time the mobile device may evaluate the information about the mainlobe of the signal from the base station, and the mobile device may becaused to move to a region having a higher or the highest SNR from themain lobe. In accordance with the second aspect, the directioninformation included in the signal from the base station is not theestimated DoA information of the signal from the mobile device, but thedirection of the beam of the second signal, which may be a beam closestto the estimated DoA.

In accordance with the second aspect the present invention provides anapparatus, like a mobile device, including an antenna and a transceiver.The transceiver receives from a transmitter, like a base station, asignal via the antenna, which includes information about a direction ofa main lobe of the signal transmitted by the transmitter. The apparatusincludes a signal processing unit which estimates a direction of a mainlobe of the signal received from the transmitter, and indicates, using aposition of the apparatus and the estimated direction of the main lobeof the signal, a direction in which the apparatus should move to improvea communication with the transmitter.

In accordance with embodiments of the second aspect, the mobile devicemay receive a signal from a base station indicative of a main lobedirection of the beam sent out by the base station, and on the basis ofthis information the direction of the main lobe may be determined so asto indicate a direction into which the mobile device should be moved forimproving the communication with the base station. No beacon signal maybe send by the mobile device, rather, the base station may be configuredto signal a beam direction within a beam transmitted. The signaling ofthe beam direction may be unique and different for each beam. Thedirection of the beam may be defined with respect to an anchor point,for example the centroid of an antenna array of the base station. Also,the orientation of the anchor point or the orientation of the antennaarray may be provided, for example within a predefined, fixed coordinatesystem in which the base station and mobile device are located, and atthe antenna array an angle at which the beam arrives at the antennaarray may be indicated. The angle together with the known orientation ofthe antenna array in the space defined by the coordinate system providesthe DoA information. As mentioned above, the coordinate system may bereferred to as a reference coordinate system and may include a Cartesiancoordinate system, a polar coordinate system or a geographic coordinatesystem. In accordance with further embodiments, the transceiver maytransmit a beacon signal via the antenna, and a signal from the basestation includes information about a direction of a main lobe of thesignal, which is closest to a direction of arrival of the beacon signalat the base station.

FIG. 2 schematically represents an embodiment of the first inventiveaspect in which a mobile device, responsive to a beacon signal sent to abases station, receives from the base station information that may beused for estimating its position and/or improving the performance of acommunication with the base station. A mobile device UE and a basestation BS are schematically represented. The base station BS includes aplurality of antennas or an antenna array ANT_(BS) also referred to as amulti-antenna transmitter/receiver point (TRP). The mobile device UEincludes one or more antennas, not depicted in FIG. 2 , and transmits abeacon signal 100 that is received at the base station BS. The beaconsignal may include a unique signature or another unique identificationassociating the beacon signal 100 uniquely with the mobile device UE. Inaddition, the beacon signal 100 includes the request indicating to thebase station BS that the mobile device UE needs beacon signal receiveinformation at the base station BS, i.e. information about the specificsof how the beacon signal 100 is received by the receiver. At the basestation BS, responsive to the request in the beacon signal, a directionof arrival (DoA) of the signal 100 is calculated or estimated. The basestation BS generates a signal 102, also referred to as a responsesignal, that is transmitted to the mobile device UE. The signal 102includes the estimated DoA of the beacon signal 100 as well asinformation representing a position of the base station BS, for exampleinformation about the anchor point.

In accordance with embodiments, the beacon signal 100 may be defined bya protocol or by a communication standard as used in the communicationnetwork. The beacon signal may be a random-based generated sequencewhich is unique for each mobile device UE in the system, or it may be afixed sequence that is provided for the mobile device. The base station,in accordance with embodiments, may transmit via the TRP a beamformedsignal including the estimated DoA information for the mobile device UEas well as information allowing the mobile device UE to determine theposition of the base station BS. In accordance with embodiments, thebeamformed signal 102 may be transmitted in a horizontal and verticaldirection which are estimated, on the basis of the DoA information, tobe the direction in which the mobile device UE is located. The signal102 may include information that allow only the requesting mobile deviceUE to restore the message included in the signal 102, for example theinformation may be correlated with the unique identification of themobile device UE such that only the intended mobile device UE mayrestore the message included in the signal 102.

The DoA information estimated or predicted by the bases station mayinclude an horizontal angle and a vertical angle, or a direction vectorincluding one or more components of a coordinate system in which themobile device and the base station are located. The horizontal angle mayrange from 0° to 360° or from 0° to 180°, and the vertical angle mayrange from 0° to 180° or from 0° to 360°, or the horizontal and verticalangles may range from −180° to 180°, or the horizontal and verticalangles are indicated in radiant. In accordance with other embodiments,the DoA information may include a two- or three-dimensional vectorhaving respective components of a coordinate system in which the mobiledevice and the base station are located, for example the x-, y-,z-components of a Cartesian coordinate system as indicated in FIG. 2 .

The position of the base station BS may be indicated by providing a two-or three-dimensional vector indicating the respective components of thecoordinate system in which the two entities are provided, or anidentification may be transmitted, in case a lookup table or map isavailable to the mobile device UE for access. The lookup table or mapincludes positions associated with the respective base stationidentifications.

To improve the robustness of the signal transmission from the basestation to the mobile device UE, in accordance with further embodiments,the base station may transmit the signal 102 several times. In casemultiple antenna arrays are provided at the base station, multiple beamsmay be transmitted at the same time and frequency to provide aquasi-orthogonal transmission in the spatial domain, e.g., when aplurality of mobile devices, like drones, within the coverage area ofthe base station need to be provided with information allowing them todetermine their positions. In accordance with other embodiments, spatialdiversity using non-orthogonal beams may be provided to increase thereceive SNR, e.g., when a robust information transmission to one mobiledevice is needed. The base station may transmit multiple beams onorthogonal resources, such as time, frequency or code domain. The one ormore beams transmitting the signal 102 may be generated at the basestation BS using a fixed codebook, or using the information about theposition of the mobile device.

The inventive approach as described above with reference to FIG. 2 isadvantageous as it does not require a dedicated data communication linkfrom the mobile device UE to the base station BS, rather, in accordancewith embodiments only a beacon signal including the additionalinformation mentioned above is broadcast or transmitted by the mobiledevice. Responsive to the beacon signal at the base station BS, aone-way transmission back to the mobile device UE is sufficient forproviding the information to the mobile device UE on the basis of whichfurther estimations/improvements can be performed, as shall be describednow with reference to further embodiments.

In accordance with an embodiment, the information from the signal 102may be used by the mobile device UE to estimate its own position withinthe coordinate system in which the mobile device UE and the base stationBS are arranged.

In accordance with one embodiment, the mobile device UE, using thesignal 102 received from the base station BS, determines a distancebetween the mobile device UE and the base station BS. On the basis ofthe position of the base station BS and the direction into which thebase station BS is located with respect to the mobile device UE, assignaled by the signal 102, and based on the calculated distance to thebase station BS a position of the mobile device UE is determined at themobile device UE. Thus, only a limited number of calculations andreduced calculation power is needed at the mobile device UE, which makesthe inventive approach suitable for mobile devices, such a fast movingdrones, which only have limited signal processing and batterycapacities. The distance between the mobile device UE and the basestation BS may be determined at the mobile device UE on the basis of thereceived power, for example the received signal strength indicator RSSI,the signal-to-noise ratio (SNR) or other metrics. In accordance withother embodiments, the distance may be determined on the basis of anestimation of the time of arrival (ToA) of the signal 102 which mayinclude additional position reference signals (PRS) sent out by the basestation BS. The PRS sequences are downlink signals that are designed forpositioning purposes in a broadcast to the mobile devices in a cellserved by a base station, and the ToA measurement, in the mobile deviceUE, is related to the geometric distance between the mobile device UEand the base station BS.

FIG. 3 shows a schematic representation of another embodiment of theinventive approach for estimating a position of a mobile device UE. Inaccordance with the embodiment of FIG. 3 , the mobile device UE receivesa plurality of response signals from a plurality of base stations thatreceived and processed the beacon signal 100 sent out from the mobiledevice UE. In FIG. 3 , two base stations BS₁ and BS₂ are shown, althoughmore than two base stations may be used. Base station BS₁ corresponds tothe base station explained above with reference to FIG. 2 , and basestation BS₂ also receives the beacon signal 100 and provides in theresponse signal 102 ₂, which sent back to the mobile device UE, theinformation about the DoA of the beacon signal 100 at the base stationBS₂ as well as information allowing the determination of the position ofthe base station BS₂. In the embodiment of FIG. 3 , the mobile device UEdetermines its location within the coordinate system in which allentities are located, on the basis of the DoA information included inthe response signals 102 ₁ and 102 ₂ from the two base stations BS₁ andBS₂ as well as on the basis of the information about the positions ofthe base stations BS₁, BS₂ included in the signals 102 ₁ and 102 ₂.

FIG. 4 depicts a further embodiment of the inventive approach inaccordance with which the information provided from the base stationtowards the mobile device UE is used for improving the communicationbetween the mobile device UE and the base station. The signal 102provided by the base station in response to the beacon signal mayinclude further information about a transmit signal 104 and a directionof a main lobe 106 thereof. The mobile device mobile device UE mayobtain the beam direction as part of the signal 102 and the informationposition about the base station so as to determine where the main lobe106 is directed to. In accordance with further embodiments, on the basisof the position of the mobile device UE and the information about thedirection of the main lobe the mobile device UE may determine adirection into which it should move to be closer to the main lobe forimproving the communication, for example the link SNR. The position ofthe mobile device UE may be determined by conventional approaches or inaccordance with the above described embodiments. The embodimentdescribed with reference to FIG. 4 may also be seen as providing acompass enabling the mobile device to improve the link quality by movingtowards the main lobe, i.e., an improvement of the communication may beachieved without changing a configuration in the network or at the basestation. For example, in case a user needs a large download, the compassfunction may be used to signal the user a direction to move therebyimproving the SNR and, therefore, the downlink throughput.

In accordance with further embodiments, rather than providinginformation about the main lobe in response to the beacon signaltransmitted by the mobile device UE, the base station may be implementedin such a way that the base station, when transmitting a signal beingbeamformed includes for each beam a direction information about the beamso that a mobile device UE, on the basis of the received informationabout the direction of the main lobe may indicate a direction into whichthe mobile device UE should be moved for improving the communication.

In accordance with the embodiments, rather than providing the DoAinformation in the signal 102, information about the main lobe may beprovided, for example a main lobe direction may be indicated in thereturn signal 102 which is closest to the estimated DoA.

The inventive approach, as described above, provides for significantimprovements over conventional approaches in that a low complexityposition estimation at the mobile device is enabled using only thereceived DoA and position information at the mobile device. This allowsfor low energy consumption at the mobile device, and in the embodiments,in which the response signal 102 is correlated with the unique ID of themobile device, the position information is secure and private to themobile device and, the finally estimated position is not known at thebase station but only at the mobile device. In addition, the mobiledevice does not need to be equipped with additional receivers, like GNSSreceivers or WiFi receivers.

Embodiments of the present invention may be implemented in a wirelesscommunication system as depicted in FIG. 1 including base stations,users, like mobile terminals or IoT devices. FIG. 5 is a schematicrepresentation of a wireless communication system 300 for communicatinginformation between a transmitter TX and a receiver RX. The transmitterTX includes a plurality of antennas ANT_(TX) or an antenna array havinga plurality of antenna elements. The receiver RX includes at least oneantenna ANT_(RX). In other embodiments, the receiver RX may include morethan one antenna. As is indicated by the arrow 302 signals arecommunicated between the transmitter TX and the receiver RX via awireless communication link, like a radio link. The transmission may bein accordance with the one of the techniques described above withreference to FIG. 1

The signaling between the transmitter TX and the receiver RX is inaccordance with the above described embodiments of the presentinvention. For example, the receiver RX includes a transceiver 304 whichtransmits a first signal via the antenna ANT_(RX). The first signalincludes a unique identification of the receiver RX and a request forreceive information about the first signal at the transmitter TX. Thetransceiver 304 receives from the transmitter TX a second signal via theantenna ANT_(RX). The second signal includes first information about adirection of arrival (DoA) of the first signal transmitter TX and secondinformation indicative of a location of the transmitter TX.

In accordance with embodiments, as described above, the receiver RXfurther includes a signal processing unit 306. The receiver RX mayreceive, using the from at least one further transmitter TX a furthersecond signal via the antenna ANT_(RX). The further second signalincludes first information about a direction of arrival (DoA) of thefirst signal at the further transmitter TX and second informationindicative of a location of the further transmitter TX. The signalprocessing unit 306 estimates a position of the receiver TX using thefirst and second information in the second signal received from thetransmitter TX and in the further second signal received from the atleast one further transmitter TX. In accordance with yet otherembodiments, the signal processing unit 306 estimates a direction of amain lobe of the second signal using the first and second information inthe second signal received from the transmitter TX. The signalprocessing unit 306 may then indicate, using a position of the receiverRX that may be determined as described above or by other means, and theestimated direction of the main lobe of the second signal, a directionin which the receiver RX should move to improve a communication with thetransmitter TX.

In accordance with other embodiments, no first or beacon signal istransmitted by the receiver. The transceiver 304 of the receiver RXreceives from the transmitter TX a signal via the antenna ANT_(RX),which includes information about a direction of a main lobe of thesignal transmitted by the transmitter TX. The signal processing unit 306estimates a direction of a main lobe of the signal received from thetransmitter TX, and indicates, using a position of the receiver RX andthe estimated direction of the main lobe of the signal, a direction inwhich the receiver RX should move to improve a communication with thetransmitter TX.

In accordance with embodiments, the transmitter TX may comprise atransceiver 308 to receive a first signal via the plurality of antennasANT_(TX). The first signal includes a unique identification of thereceiver RX which transmits the first signal and a request for receiveinformation about the first signal at the transmitter TX. In accordancewith embodiments, the transmitter TX includes a signal processing unit310 which estimates a direction of arrival (DoA) of the first signal.The transceiver 308 transmits to the receiver RX a second signal via theplurality of antennas ANT_(TX). The second signal includes firstinformation about the estimated direction of arrival (DoA) of the firstsignal at the transmitter TX and second information indicative of alocation of the transmitter TX.

Although some aspects of the described concept have been described inthe context of an apparatus, it is clear that these aspects alsorepresent a description of the corresponding method, where a block or adevice corresponds to a method step or a feature of a method step.Analogously, aspects described in the context of a method step alsorepresent a description of a corresponding block or item or feature of acorresponding apparatus.

Various elements and features of the present invention may beimplemented in hardware using analog and/or digital circuits, insoftware, through the execution of instructions by one or more generalpurpose or special-purpose processors, or as a combination of hardwareand software. For example, embodiments of the present invention may beimplemented in the environment of a computer system or anotherprocessing system. FIG. 6 illustrates an example of a computer system400. The units or modules as well as the steps of the methods performedby these units may execute on one or more computer systems 400. Thecomputer system 400 includes one or more processors 402, like a specialpurpose or a general purpose digital signal processor. The processor 402is connected to a communication infrastructure 404, like a bus or anetwork. The computer system 400 includes a main memory 406, e.g., arandom access memory (RAM), and a secondary memory 408, e.g., a harddisk drive and/or a removable storage drive. The secondary memory 408may allow computer programs or other instructions to be loaded into thecomputer system 400. The computer system 400 may further include acommunications interface 410 to allow software and data to betransferred between computer system 400 and external devices. Thecommunication may be in the form electronic, electromagnetic, optical,or other signals capable of being handled by a communications interface.The communication may use a wire or a cable, fiber optics, a phone line,a cellular phone link, an RF link and other communications channels 412.

The terms “computer program medium” and “computer readable medium” areused to generally refer to tangible storage media such as removablestorage units or a hard disk installed in a hard disk drive. Thesecomputer program products are means for providing software to thecomputer system 400. The computer programs, also referred to as computercontrol logic, are stored in main memory 406 and/or secondary memory408. Computer programs may also be received via the communicationsinterface 410. The computer program, when executed, enable the computersystem 400 to implement the present invention. In particular, thecomputer program, when executed, enable processor 402 to implement theprocesses of the present invention, such as any of the methods describedherein. Accordingly, such a computer program may represent a controllerof the computer system 400. Where the disclosure is implemented usingsoftware, the software may be stored in a computer program product andloaded into computer system 400 using a removable storage drive, aninterface, like communications interface 410.

The implementation in hardware or in software may be performed using adigital storage medium, for example cloud storage, a floppy disk, a DVD,a Blue-Ray, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory,having electronically readable control signals stored thereon, whichcooperate (or are capable of cooperating) with a programmable computersystem such that the respective method is performed. Therefore, thedigital storage medium may be computer readable.

Some embodiments according to the invention comprise a data carrierhaving electronically readable control signals, which are capable ofcooperating with a programmable computer system, such that one of themethods described herein is performed.

Generally, embodiments of the present invention may be implemented as acomputer program product with a program code, the program code beingoperative for performing one of the methods when the computer programproduct runs on a computer. The program code may for example be storedon a machine readable carrier.

Other embodiments comprise the computer program for performing one ofthe methods described herein, stored on a machine readable carrier. Inother words, an embodiment of the inventive method is, therefore, acomputer program having a program code for performing one of the methodsdescribed herein, when the computer program runs on a computer.

A further embodiment of the inventive methods is, therefore, a datacarrier (or a digital storage medium, or a computer-readable medium)comprising, recorded thereon, the computer program for performing one ofthe methods described herein. A further embodiment of the inventivemethod is, therefore, a data stream or a sequence of signalsrepresenting the computer program for performing one of the methodsdescribed herein. The data stream or the sequence of signals may forexample be configured to be transferred via a data communicationconnection, for example via the Internet. A further embodiment comprisesa processing means, for example a computer, or a programmable logicdevice, configured to or adapted to perform one of the methods describedherein. A further embodiment comprises a computer having installedthereon the computer program for performing one of the methods describedherein.

In some embodiments, a programmable logic device (for example a fieldprogrammable gate array) may be used to perform some or all of thefunctionalities of the methods described herein. In some embodiments, afield programmable gate array may cooperate with a microprocessor inorder to perform one of the methods described herein. Generally, themethods are preferably performed by any hardware apparatus.

The above described embodiments are merely illustrative for theprinciples of the present invention. It is understood that modificationsand variations of the arrangements and the details described herein willbe apparent to others skilled in the art. It is the intent, therefore,to be limited only by the scope of the impending patent claims and notby the specific details presented by way of description and explanationof the embodiments herein.

While this invention has been described in terms of several embodiments,there are alterations, permutations, and equivalents which fall withinthe scope of this invention. It should also be noted that there are manyalternative ways of implementing the methods and compositions of thepresent invention. It is therefore intended that the following appendedclaims be interpreted as including all such alterations, permutationsand equivalents as fall within the true spirit and scope of the presentinvention.

REFERENCES

-   [1] 3GPP, “LTE Positioning Protocol (LPP) (Release 13)”, 3rd    Generation Partnership Project, March 2016-   [2] 3GPP, “LTE Positioning Protocol A (LPPa) (Release 13)”, 3rd    Generation Partnership Project, March 2016-   [3] S. Fischer, “Observed Time Difference Of Arrival (OTDOA)    positioning in 3GPP LTE”, Qualcomm White Pap, vol. 1, pp. 1-62, June    2014-   [4] Misra and P. Enge, “Global Positioning System: Signals,    Measurements and Performance Second Edition”, Lincoln, Mass.:    Ganga-Jamuna Press, 2006-   [5] Y. H. Nam, M. S. Rahman, Y. Li, G. Xu, E. Onggosanusi, J. Zhang    and J. Y. Seal, “Full dimension MIMO for LTE-Advanced and SG”,    Information Theory and Applications Workshop (ITA), 2015, pp.    143-148, February 2015-   [6] 3GPP, “Study on Elevation Beamforming/Full-Dimension (FD) MIMO    for LTE”, 3rd Generation Partnership Project, vol. V13.0.0, July    2015-   [7] Y. Kirn, H. Ji, J. Lee, Y.-H. Nam, B. L. Ng, I. Tzanidis, Y. Li    and J. Zhang, “Full dimension mimo (FD-MIMO): the next evolution of    MIMO in LTE systems”, Wireless Communications, IEEE, vol. 21, pp.    26-33, April 2014-   [8] US 2016/0295366 A1-   [9] US 2004/0072579 A1-   [10] US 2013/0028246 A1-   [11] US 2014/0162704 A1

The invention claimed is:
 1. A mobile device for a wirelesscommunication network, wherein the wireless communication networkincludes one or more base stations, the mobile device comprising: anantenna; and a transceiver, and a signal processor, wherein thetransceiver is configured to transmit a first signal via the antenna,the first signal comprising a unique identification of the mobile deviceand requesting a network entity of the wireless communication network totransmit to the mobile device a direction into which at least one basestation is located with respect to the mobile device together withlocation information about a location of the base station, and followingthe transmitting of the first signal, receive a second signal via theantenna, the second signal comprising the direction into which the atleast one base station is located and the location information about thelocation of the base station, and wherein the signal processor isconfigured to estimate a position of the mobile device using thedirection and the location information included in the second signal. 2.The mobile device according to claim 1, wherein the direction comprisesan horizontal angle and a vertical angle, or a direction vectorcomprising one or more components of a coordinate system in which themobile device and the base station are located.
 3. The mobile deviceaccording to claim 1, wherein the horizontal angle ranges from 0° to360° or from 0° to 180°, and the vertical angle ranges from 0° to 180°or from 0° to 360°, or the horizontal and vertical angles range from−180° to 180°, or the horizontal and vertical angles are indicated inradiant.
 4. The mobile device according to claim 1, wherein the locationinformation comprises data corresponding to a position or to anidentification of the base station.
 5. The mobile device according toclaim 1, wherein the first signal is defined in accordance with acommunication protocol/standard, and comprises a random-based generatedsequence, which is unique for the mobile device, or a fixed sequence,which is unique for the mobile device.
 6. The mobile device according toclaim 1, wherein the respective second signals are beamformed signals.7. The mobile device according to claim 1, wherein the second signal iscorrelated with the unique identification of the mobile device such thatonly an intended mobile device is able to restore the direction and thelocation information.
 8. A network entity for a wireless communicationnetwork, wherein the wireless communication network includes one or moremobile devices and one or more base stations, wherein the network entityis configured to receive from a mobile device of the wirelesscommunication network a first signal comprising a unique identificationof the mobile device and requesting the network entity to transmit tothe mobile device a direction into which at least one base station islocated with respect to the mobile device together with locationinformation about a location of the base station, and following thereceiving of the first signal, transmit to the mobile device a secondsignal, the second signal comprising the direction into which the atleast one base station is located and the location information about thelocation of the base station so as to allow the mobile device toestimate its position using the direction and the location informationincluded in the second signal.
 9. The network entity according to claim8, wherein the direction comprises an horizontal angle and a verticalangle, or a direction vector comprising one or more of a coordinatesystem in which the mobile device and the base station are located. 10.The network entity according to claim 8, wherein the horizontal angleranges from 0° to 360° or from 0° to 180°, and the vertical angle rangesfrom 0° to 180° or from 0° to 360°, or the horizontal and verticalangles range from −180° to 180° or from −90° to 90°, or the horizontaland vertical angles are indicated in radiant.
 11. The network entityaccording to claim 8, wherein the location information comprises datacorresponding to a position or to an identification of the base station.12. The network entity according to claim 8, wherein the first signal isdefined in accordance with a communication protocol/standard, andcomprises a random-based generated sequence, which is unique for themobile device, or a fixed sequence, which is unique for the mobiledevice.
 13. The network entity according to claim 8, wherein the secondsignal is a beamformed signal.
 14. The network entity according to claim8, wherein the second signal is correlated with the uniqueidentification of the mobile device such that only an intended mobiledevice is able to restore the direction and the location information.15. A wireless communication network, comprising: one or more mobiledevices, one or more base stations, and a network entity, wherein thenetwork entity is configured to receive from a mobile device of thewireless communication network a first signal comprising a uniqueidentification of the mobile device and requesting the network entity totransmit to the mobile device a direction into which at least one basestation is located with respect to the mobile device together withlocation information about a location of the base station, and followingthe receiving of the first signal, transmit to the mobile device asecond signal, the second signal comprising the direction into which theat least one base station is located and the location information aboutthe location of the base station, and wherein the mobile device isconfigured to estimate its position using the direction and the locationinformation included in the second signal.
 16. A method, comprising:transmitting a first signal via an antenna of a mobile device of awireless communication system, the first signal comprising a uniqueidentification of the mobile device and requesting a network entity ofthe wireless communication network to transmit to the mobile device adirection into which the at least one base station of the wirelesscommunication system is located together with location information abouta location of the base station, following the transmitting of the firstsignal, receiving, from the network entity a second signal via theantenna of the mobile device, the second signal comprising the directioninto which the at least one base station of the wireless communicationsystem is located and the location information about the location of thebase station, and estimating, by the mobile device, a position of themobile device using the direction and the location information includedin the second signal.